Description: The Flow Cytometry Shared Resource assists UCLA research projects requiring flow cytometric techniques by making available both stateof- the-art flow cytometry equipment and knowledgeable personnel to operate the equipment and to provide consultation on experimental design and performance. The facility consists of two analytic flow cytometers and two FACStarplus sorters with state-of-the-art computer interfaces to facilitate data collection and analysis. The use of the Flow Cytometer Facility is based on hourly use units, which have a different chargeback cost per hour, ranging from $30 per hour to $90 per hour, depending upon the intensity of the services provided. Over the past four years, the total usage of this facility has ranged from 3043 hours per year in 1993, up to 4764 hours per year in 1995, with 3541 hours estimated for 1996. Over the past four years there have been 74 users from the Center and 55 non- Cancer Center users. However, Cancer Center users have preferred access to the facility and Center faculty use it to a far greater degree such that 88 percent of the activity of the facility involves usage by Center members. The majority of Cancer Center users are peer reviewed, and 61.7 percent of the total use of this facility is by Cancer Center members involved in peer reviewed projects.